This legal knot was quickly and decisively cut by General Mansfield, in an unanswerable decision.

"I know the d——d ship has surrendered," he said. "But we haven't." And the firing continued.

The Merrimac, not being able to seize her prize, opened fire with hot shot on the Congress, and quickly set her on fire. Night was now at hand, and the conquering iron-clad drew off. The Congress continued to burn, her loaded guns roaring her requiem one after another, as the fire spread along her decks. About one o'clock her magazine was reached, and she blew up with a tremendous explosion, the shock being so great as to prostrate many of those on the shore.

So ended that momentous day. It had shown one thing conclusively, that "wooden walls" could no longer "rule the wave." Iron had proved its superiority in naval construction. The next day was to behold another novel sight,—the struggle of iron with iron.

Morning came. The atmosphere was hazy. Only as the mist slowly lifted were the gladiators of that liquid arena successively made visible. Here, just above the water, defiantly floated the flag of the sunken Cumberland. There smoked the still-burning hull of the Congress. Here, up the bay, steamed the Merrimac, with two attendants, the Yorktown and the Patrick Henry. Yonder lay the great hull of the steam-frigate Minnesota, which had taken some part in the battle of the day before, but had unfortunately gone ashore on a mud-bank, from which the utmost efforts failed to force her off. Other Union naval vessels were visible in the distance.

The Merrimac made her way towards the Minnesota, as towards a certain prey. Her commander felt confident that an hour or two would enable him to reduce this great vessel to the condition of her recent companions.

Yet an odd sight met his vision. Alongside the Minnesota floated the strangest-looking craft that human eye had ever gazed upon. An insignificant affair it appeared; a "cheese-box on a raft" it was irreverently designated. The deck, a level expanse of iron, came scarcely above the surface. Above it rose a circular turret, capable of being revolved, and with port-holes for two great guns, among the largest up to that time used in naval warfare.

How this odd contrivance came there so opportunely may be briefly told. It was the conception of John Ericsson, the eminent Swedish engineer, and was being rapidly built in New York while the Merrimac was being plated with thick iron bars in Norfolk. A contest for time took place between these two unlike craft. Spies were in both places, to report progress. Fortunately, the Monitor was finished a day or two before her competitor. Immediately she steamed away for Hampton Roads. The passage was a severe one. Three days were consumed, during which the seas swept repeatedly over the low deck, the men being often half suffocated in their confined quarters, the turret alone standing above the water. As they approached Fortress Monroe the sound of cannonading was heard. Tarrying but a few minutes at the fort, the Monitor, as this odd vessel had been named, approached the Minnesota, and reached her side at a late hour of the night.